1. Field of the Invention
This invention relates to dye complexing polymers, and, more particularly, to water soluble poly(vinylpyridine betaines) containing a quaternary nitrogen and a carboxylate salt. The polymers herein have effective dye transfer inhibitor (DTI) properties for use, for example, laundry detergent and fabric softener compositions.
2. Description of the Prior Art
Dye complexing polymers have been used in laundry detergent and fabric softener compositions. In such application, during washing a mixture of colored and white fabrics, some of the dyes may bleed out of a colored fabric under washing conditions. The degree of bleeding is influenced by the structure of the dye, the type of cloth and the pH, temperature and mechanical efficiency of the agitation process. The bled dye in the wash liquor can be totally innocuous and get washed off in the wash liquor. However, in reality, this fugitive dye has a tendency to redeposit either onto the same fabric or onto another fabric leading to patches and an ugly appearance of the washed material. This redeposition of the bled dye can be inhibited in several ways. One method is to introduce a DTI compound which can complex with the fugitive dye and get washed off thus preventing redeposition.
Polyvinylpyrrolidone (PVP), by virtue of its dye complexation ability, has been used to inhibit dye deposition during washing of colored fabrics under laundry conditions. The performance of PVP as a DTI, however, is adversely affected by the presence of anionic surfactants in the washing process.
Other polymers which have been used as DTIs in laundry detergent compositions include polyvinylpyridine N-oxide (PVPNO); polyvinylimidazole (PVI) and copolymers of polyvinylpyridine and polyvinylimidazole (PVP-PVI).
The prior art in this field is represented by the following patents and publications:
______________________________________ Patent Subject Matter ______________________________________ (1) JP 53-50732 Formulas Nos. 3, 6 and (1) are water insoluble compounds and polymers used in printing ink compositions; (2) PCT/US94/06849 Dye inhibiting composition polymers of WO 95/03390 PVP, polyamine N-oxide, vinylimidazole are used in laundry detergent compositions; (3) U.S. Pat. No. Polyamine N-oxide polymers described 5,460,752 for use in laundry detergent compositions; (4) EPA 664335 A1 Polysulfoxide polymers; (5) PCT/US93/10542 Laundry compositions include polyamine- WO 94/11473 N-oxide and brighteners and surfactants; (6) PCT/EP93/02851 PVP and PVI are present in laundry WO 94/10281 compositions; (7) PCT/US94/11509 Poly(4-vinylpyridine-N-oxide) (PVPNO) WO 95/13354 and copolymers of VP and VI are described; (8) EP 754748 A1 Vinylpyridine copolymers and formic acid; (9) EP 0664332 A1 Polyamine oxide polymers; (10) U.S. Pat. No. PVPNO + clay softening; 5,604,197 (11) U.S. Pat. No. PVPNO; 5,458,809 (12) U.S. Pat. No. PVPNO and PVP-VI; 5,466,802 (13) U.S. Pat. No. Copolymers of VP or VI; vinylpyridine 5,627,151 or dimethylaminoethyl methacrylate or dimethylaminopropylmethacrylamide, including up to 20% vinylacetate; (14) PCT/US95/04019 PVPNO, PVP, PVP-PI and copolymers of WO 95/27038 VP and VI; (15) EPA 628624 A1 PVPNO with protease; (16) DE 4224762 A1 VP polymers; (17) J. Polymer Water-insoluble poly(4-vinylpyridine) Sci. 26, compounds and polymers No. 113, p. 25-254 (1957) ______________________________________
Accordingly, it is an object of this invention to provide new and improved water soluble dye complexing polymers.
Another object herein is to provide water soluble dye transfer inhibitor (DTI) polymers which are effective in laundry detergent compositions containing an anionic surfactant.
A feature of the invention is the provision of a water soluble poly(vinylpyridine betaine) containing a quaternary nitrogen and a carboxylate salt.
Another feature of the invention is the provision of laundry detergent compositions containing such new and improved water soluble polymers, which exhibit particularly effective dye transfer inhibition properties during the washing process even in the presence of anionic surfactants.
Among the other objects and features of the invention is to provide such polymers having dye complexing properties useful in fabric softener and textile dye treatment compositions.